ChaiScript/include/chaiscript/language/chaiscript_eval.hpp

900 lines
29 KiB
C++

// This file is distributed under the BSD License.
// See "license.txt" for details.
// Copyright 2009, Jonathan Turner (jturner@minnow-lang.org)
// and Jason Turner (lefticus@gmail.com)
// http://www.chaiscript.com
#ifndef CHAISCRIPT_EVAL_HPP_
#define CHAISCRIPT_EVAL_HPP_
#include <map>
namespace chaiscript
{
/**
* Helper function that will set up the scope around a function call, including handling the named function parameters
*/
template <typename Eval_System>
const Boxed_Value eval_function (Eval_System &ss, TokenPtr node, const std::vector<std::string> &param_names, const std::vector<Boxed_Value> &vals) {
ss.new_scope();
for (unsigned int i = 0; i < param_names.size(); ++i) {
ss.add_object(param_names[i], vals[i]);
}
Boxed_Value retval;
try {
retval = eval_token(ss, node);
ss.pop_scope();
} catch (const Return_Value &rv) {
retval = rv.retval;
ss.pop_scope();
} catch (...) {
ss.pop_scope();
throw;
}
return retval;
}
/**
* Evaluates the top-level file node
*/
template <typename Eval_System>
Boxed_Value eval_file(Eval_System &ss, TokenPtr node) {
Boxed_Value retval;
unsigned int i;
for (i = 0; i < node->children.size(); ++i) {
retval = eval_token(ss, node->children[i]);
}
return retval;
}
/**
* Evaluates a variable or function name identifier
*/
template <typename Eval_System>
Boxed_Value eval_id(Eval_System &ss, TokenPtr node) {
if (node->text == "true") {
return Boxed_Value(true);
}
else if (node->text == "false") {
return Boxed_Value(false);
}
else {
try {
return ss.get_object(node->text);
}
catch (std::exception &) {
throw Eval_Error("Can not find object: " + node->text, node);
}
}
}
/**
* Evaluates a floating point number
*/
template <typename Eval_System>
Boxed_Value eval_float(Eval_System &, TokenPtr node) {
return Boxed_Value(double(atof(node->text.c_str())));
}
/**
* Evaluates an integer
*/
template <typename Eval_System>
Boxed_Value eval_int(Eval_System &, TokenPtr node) {
return Boxed_Value(atoi(node->text.c_str()));
}
/**
* Evaluates a quoted string
*/
template <typename Eval_System>
Boxed_Value eval_quoted_string(Eval_System &, TokenPtr node) {
return Boxed_Value(node->text);
}
/**
* Evaluates a char group
*/
template <typename Eval_System>
Boxed_Value eval_single_quoted_string(Eval_System &, TokenPtr node) {
if (node->text.size() == 1) {
return Boxed_Value(char(node->text[0]));
}
else {
return Boxed_Value(char((int)node->text[0] * 0xff + (int)node->text[0]));
}
}
/**
* Evaluates a string of equations in reverse order so that the right-most side has precedence
*/
template <typename Eval_System>
Boxed_Value eval_equation(Eval_System &ss, TokenPtr node) {
Boxed_Value retval;
unsigned int i;
retval = eval_token(ss, node->children.back());
if (node->children.size() > 1) {
for (i = node->children.size()-3; ((int)i) >= 0; i -= 2) {
if (node->children[i+1]->text == "=") {
Boxed_Value lhs = eval_token(ss, node->children[i]);
try {
if (lhs.is_unknown())
{
retval = ss.call_function("clone", Param_List_Builder() << retval);
}
Param_List_Builder plb;
plb << lhs;
plb << retval;
try {
retval = ss.call_function(node->children[i+1]->text, plb);
}
catch(const dispatch_error &){
throw Eval_Error("Mismatched types in equation", node->children[i+1]);
}
}
catch(const dispatch_error &){
throw Eval_Error("Can not clone right hand side of equation", node->children[i+1]);
}
}
else if (node->children[i+1]->text == ":=") {
Boxed_Value lhs = eval_token(ss, node->children[i]);
if (lhs.is_unknown() || type_match(lhs, retval)) {
lhs.assign(retval);
}
else {
throw Eval_Error("Mismatched types in equation", node->children[i+1]);
}
}
else {
Param_List_Builder plb;
plb << eval_token(ss, node->children[i]);
plb << retval;
try {
retval = ss.call_function(node->children[i+1]->text, plb);
}
catch(const dispatch_error &){
throw Eval_Error("Can not find appropriate '" + node->children[i+1]->text + "'", node->children[i+1]);
}
}
}
}
return retval;
}
/**
* Evaluates a variable declaration
*/
template <typename Eval_System>
Boxed_Value eval_var_decl(Eval_System &ss, TokenPtr node) {
try {
ss.add_object(node->children[0]->text, Boxed_Value());
}
catch (reserved_word_error &rwe) {
throw Eval_Error("Reserved word used as variable '" + node->children[0]->text + "'", node);
}
return ss.get_object(node->children[0]->text);
}
/**
* Evaluates binary boolean operators. Respects short-circuiting rules.
*/
template <typename Eval_System>
Boxed_Value eval_expression(Eval_System &ss, TokenPtr node) {
Boxed_Value retval;
unsigned int i;
retval = eval_token(ss, node->children[0]);
if (node->children.size() > 1) {
for (i = 1; i < node->children.size(); i += 2) {
bool lhs;
try {
lhs = boxed_cast<bool &>(retval);
}
catch (const bad_boxed_cast &) {
throw Eval_Error("Condition not boolean", node);
}
if (node->children[i]->text == "&&") {
if (lhs) {
retval = eval_token(ss, node->children[i+1]);
}
else {
retval = Boxed_Value(false);
}
}
else if (node->children[i]->text == "||") {
if (lhs) {
retval = Boxed_Value(true);
}
else {
retval = eval_token(ss, node->children[i+1]);
}
}
}
}
return retval;
}
/**
* Evaluates comparison, additions, and multiplications and their relatives
*/
template <typename Eval_System>
Boxed_Value eval_comp_add_mul(Eval_System &ss, TokenPtr node) {
Boxed_Value retval;
unsigned int i;
retval = eval_token(ss, node->children[0]);
if (node->children.size() > 1) {
for (i = 1; i < node->children.size(); i += 2) {
Param_List_Builder plb;
plb << retval;
plb << eval_token(ss, node->children[i + 1]);
try {
retval = ss.call_function(node->children[i]->text, plb);
}
catch(const dispatch_error &){
throw Eval_Error("Can not find appropriate '" + node->children[i]->text + "'", node->children[i]);
}
}
}
return retval;
}
/**
* Evaluates an array lookup
*/
template <typename Eval_System>
Boxed_Value eval_array_call(Eval_System &ss, TokenPtr node) {
Boxed_Value retval;
unsigned int i;
retval = eval_token(ss, node->children[0]);
for (i = 1; i < node->children.size(); ++i) {
Param_List_Builder plb;
plb << retval;
plb << eval_token(ss, node->children[i]);
try {
retval = ss.call_function("[]", plb);
}
catch(std::out_of_range &) {
throw Eval_Error("Out of bounds exception", node);
}
catch(const dispatch_error &){
throw Eval_Error("Can not find appropriate array lookup '[]' " + node->children[i]->text, node->children[i]);
}
}
return retval;
}
/**
* Evaluates a unary negation
*/
template <typename Eval_System>
Boxed_Value eval_negate(Eval_System &ss, TokenPtr node) {
Boxed_Value retval;
retval = eval_token(ss, node->children[0]);
Param_List_Builder plb;
plb << retval;
plb << Boxed_Value(-1.0);
try {
return ss.call_function("*", plb);
}
catch(std::exception &){
throw Eval_Error("Can not find appropriate negation", node->children[0]);
}
}
/**
* Evaluates a unary boolean not
*/
template <typename Eval_System>
Boxed_Value eval_not(Eval_System &ss, TokenPtr node) {
Boxed_Value retval;
bool cond;
try {
retval = eval_token(ss, node->children[0]);
cond = boxed_cast<bool &>(retval);
}
catch (const bad_boxed_cast &) {
throw Eval_Error("Boolean not('!') condition not boolean", node->children[0]);
}
return Boxed_Value(!cond);
}
/**
* Evaluates any unary prefix
*/
template <typename Eval_System>
Boxed_Value eval_prefix(Eval_System &ss, TokenPtr node) {
Boxed_Value retval;
retval = eval_token(ss, node->children[1]);
Param_List_Builder plb;
plb << retval;
try {
return ss.call_function(node->children[0]->text, plb);
}
catch(std::exception &){
throw Eval_Error("Can not find appropriate prefix", node->children[0]);
}
}
/**
* Evaluates (and generates) an inline array initialization
*/
template <typename Eval_System>
Boxed_Value eval_inline_array(Eval_System &ss, TokenPtr node) {
Boxed_Value retval;
unsigned int i;
try {
retval = ss.call_function("Vector", Param_List_Builder());
if (node->children.size() > 0) {
for (i = 0; i < node->children[0]->children.size(); ++i) {
try {
Boxed_Value tmp = eval_token(ss, node->children[0]->children[i]);
ss.call_function("push_back", Param_List_Builder() << retval << tmp);
}
catch (const dispatch_error &) {
throw Eval_Error("Can not find appropriate 'push_back'", node->children[0]->children[i]);
}
}
}
}
catch (const dispatch_error &) {
throw Eval_Error("Can not find appropriate 'Vector()'", node);
}
return retval;
}
/**
* Evaluates (and generates) an inline range initialization
*/
template <typename Eval_System>
Boxed_Value eval_inline_range(Eval_System &ss, TokenPtr node) {
try {
return ss.call_function("generate_range", Param_List_Builder()
<< eval_token(ss, node->children[0]->children[0]->children[0])
<< eval_token(ss, node->children[0]->children[0]->children[1]));
}
catch (const dispatch_error &) {
throw Eval_Error("Unable to generate range vector", node);
}
}
/**
* Evaluates (and generates) an inline map initialization
*/
template <typename Eval_System>
Boxed_Value eval_inline_map(Eval_System &ss, TokenPtr node) {
Boxed_Value retval;
unsigned int i;
try {
retval = ss.call_function("Map", Param_List_Builder());
for (i = 0; i < node->children[0]->children.size(); ++i) {
try {
Boxed_Value key = eval_token(ss, node->children[0]->children[i]->children[0]);
Boxed_Value slot = ss.call_function("[]", Param_List_Builder() << retval << key);
ss.call_function("=", Param_List_Builder() << slot << eval_token(ss, node->children[0]->children[i]->children[1]));
}
catch (const dispatch_error &) {
throw Eval_Error("Can not find appropriate '=' for map init", node->children[0]->children[i]);
}
}
}
catch (const dispatch_error &) {
throw Eval_Error("Can not find appropriate 'Map()'", node);
}
return retval;
}
/**
* Evaluates a function call, starting with its arguments. Handles resetting the scope to the previous one after the call.
*/
template <typename Eval_System>
Boxed_Value eval_fun_call(Eval_System &ss, TokenPtr node) {
Boxed_Value retval;
Param_List_Builder plb;
Dispatch_Engine::Stack prev_stack = ss.get_stack();
Dispatch_Engine::Stack new_stack = ss.new_stack();
unsigned int i;
if ((node->children.size() > 1) && (node->children[1]->identifier == Token_Type::Arg_List)) {
for (i = 0; i < node->children[1]->children.size(); ++i) {
plb << eval_token(ss, node->children[1]->children[i]);
}
}
Boxed_Value fn;
try {
fn = eval_token(ss, node->children[0]);
}
catch(Eval_Error &ee) {
ss.set_stack(prev_stack);
throw Eval_Error(ee.reason, node->children[0]);
}
try {
ss.set_stack(new_stack);
retval = (*boxed_cast<Proxy_Function >(fn))(plb);
ss.set_stack(prev_stack);
}
catch(const dispatch_error &e){
ss.set_stack(prev_stack);
throw Eval_Error(std::string(e.what()) + " with function '" + node->children[0]->text + "'", node->children[0]);
}
catch(Return_Value &rv) {
ss.set_stack(prev_stack);
retval = rv.retval;
}
catch(...) {
ss.set_stack(prev_stack);
throw;
}
return retval;
}
/**
* Evaluates a method/attributes invocation
*/
template <typename Eval_System>
Boxed_Value eval_dot_access(Eval_System &ss, TokenPtr node) {
Boxed_Value retval;
std::vector<std::pair<std::string, Proxy_Function > > fn;
Dispatch_Engine::Stack prev_stack = ss.get_stack();
Dispatch_Engine::Stack new_stack = ss.new_stack();
unsigned int i, j;
//todo: Please extract a single way of doing function calls between this and eval_fun_call
retval = eval_token(ss, node->children[0]);
if (node->children.size() > 1) {
for (i = 1; i < node->children.size(); ++i) {
Param_List_Builder plb;
plb << retval;
if (node->children[i]->children.size() > 1) {
for (j = 0; j < node->children[i]->children[1]->children.size(); ++j) {
plb << eval_token(ss, node->children[i]->children[1]->children[j]);
}
}
//std::string fun_name;
Boxed_Value fn;
try {
if (node->children[i]->identifier == Token_Type::Fun_Call) {
//fun_name = node->children[i]->children[0]->text;
fn = eval_token(ss, node->children[i]->children[0]);
}
else {
//fun_name = node->children[i]->text;
fn = eval_token(ss, node->children[i]);
}
}
catch(Eval_Error &ee) {
ss.set_stack(prev_stack);
throw Eval_Error(ee.reason, node->children[i]);
}
try {
//fn = ss.get_function(fun_name);
ss.set_stack(new_stack);
//retval = dispatch(fn, plb);
retval = (*boxed_cast<Proxy_Function >(fn))(plb);
ss.set_stack(prev_stack);
}
catch(const dispatch_error &e){
ss.set_stack(prev_stack);
throw Eval_Error(std::string(e.what()), node->children[i]);
}
catch(Return_Value &rv) {
ss.set_stack(prev_stack);
retval = rv.retval;
}
catch(...) {
ss.set_stack(prev_stack);
throw;
}
}
}
return retval;
}
/**
* Evaluates an if/elseif/else block
*/
template <typename Eval_System>
Boxed_Value eval_if(Eval_System &ss, TokenPtr node) {
Boxed_Value retval;
unsigned int i;
retval = eval_token(ss, node->children[0]);
bool cond;
try {
cond = boxed_cast<bool &>(retval);
}
catch (const bad_boxed_cast &) {
throw Eval_Error("If condition not boolean", node->children[0]);
}
if (cond) {
retval = eval_token(ss, node->children[1]);
}
else {
if (node->children.size() > 2) {
i = 2;
while ((!cond) && (i < node->children.size())) {
if (node->children[i]->text == "else") {
retval = eval_token(ss, node->children[i+1]);
cond = true;
}
else if (node->children[i]->text == "else if") {
retval = eval_token(ss, node->children[i+1]);
try {
cond = boxed_cast<bool &>(retval);
}
catch (const bad_boxed_cast &) {
throw Eval_Error("'else if' condition not boolean", node->children[i+1]);
}
if (cond) {
retval = eval_token(ss, node->children[i+2]);
}
}
i = i + 3;
}
}
}
return retval;
}
/**
* Evaluates a while block
*/
template <typename Eval_System>
Boxed_Value eval_while(Eval_System &ss, TokenPtr node) {
bool cond;
ss.new_scope();
try {
cond = boxed_cast<bool &>(eval_token(ss, node->children[0]));
}
catch (const bad_boxed_cast &) {
ss.pop_scope();
throw Eval_Error("While condition not boolean", node->children[0]);
}
while (cond) {
try {
eval_token(ss, node->children[1]);
try {
cond = boxed_cast<bool &>(eval_token(ss, node->children[0]));
}
catch (const bad_boxed_cast &) {
ss.pop_scope();
throw Eval_Error("While condition not boolean", node->children[0]);
}
}
catch (Break_Loop &) {
cond = false;
}
}
ss.pop_scope();
return Boxed_Value();
}
/**
* Evaluates a for block, including the for's conditions, from left to right
*/
template <typename Eval_System>
Boxed_Value eval_for(Eval_System &ss, TokenPtr node) {
bool cond;
ss.new_scope();
try {
if (node->children.size() == 4) {
eval_token(ss, node->children[0]);
cond = boxed_cast<bool &>(eval_token(ss, node->children[1]));
}
else {
cond = boxed_cast<bool &>(eval_token(ss, node->children[0]));
}
}
catch (const bad_boxed_cast &) {
ss.pop_scope();
throw Eval_Error("For condition not boolean", node);
}
while (cond) {
try {
if (node->children.size() == 4) {
eval_token(ss, node->children[3]);
eval_token(ss, node->children[2]);
cond = boxed_cast<bool &>(eval_token(ss, node->children[1]));
}
else {
eval_token(ss, node->children[2]);
eval_token(ss, node->children[1]);
cond = boxed_cast<bool &>(eval_token(ss, node->children[0]));
}
}
catch (const bad_boxed_cast &) {
ss.pop_scope();
throw Eval_Error("For condition not boolean", node);
}
catch (Break_Loop &) {
cond = false;
}
}
ss.pop_scope();
return Boxed_Value();
}
/**
* Evaluates a function definition
*/
template <typename Eval_System>
Boxed_Value eval_def(Eval_System &ss, TokenPtr node) {
Boxed_Value retval;
unsigned int i;
std::vector<std::string> param_names;
std::string annotation = node->annotation?node->annotation->text:"";
boost::shared_ptr<Dynamic_Proxy_Function> guard;
size_t numparams = 0;
std::string function_name = node->children[0]->text;
TokenPtr guardnode;
if ((node->children.size() > 2) && (node->children[1]->identifier == Token_Type::Arg_List)) {
numparams = node->children[1]->children.size();
for (i = 0; i < numparams; ++i) {
param_names.push_back(node->children[1]->children[i]->text);
}
if (node->children.size() > 3) {
guardnode = node->children[2];
}
}
else {
//no parameters
numparams = 0;
if (node->children.size() > 2) {
guardnode = node->children[1];
}
}
if (guardnode) {
guard = boost::shared_ptr<Dynamic_Proxy_Function>
(new Dynamic_Proxy_Function(boost::bind(&eval_function<Eval_System>,
boost::ref(ss), guardnode,
param_names, _1), numparams));
}
try {
ss.add(Proxy_Function
(new Dynamic_Proxy_Function(boost::bind(&eval_function<Eval_System>,
boost::ref(ss), node->children.back(),
param_names, _1), numparams,
annotation, guard)), function_name);
}
catch (reserved_word_error &rwe) {
throw Eval_Error("Reserved word used as function name '" + function_name + "'", node);
}
return retval;
}
/**
* Evaluates a lambda (anonymous function)
*/
template <typename Eval_System>
Boxed_Value eval_lambda(Eval_System &ss, TokenPtr node) {
Boxed_Value retval;
unsigned int i;
std::vector<std::string> param_names;
size_t numparams = 0;
if ((node->children.size() > 0) && (node->children[0]->identifier == Token_Type::Arg_List)) {
numparams = node->children[0]->children.size();
for (i = 0; i < numparams; ++i) {
param_names.push_back(node->children[0]->children[i]->text);
}
}
else {
//no parameters
numparams = 0;
}
return Boxed_Value(Proxy_Function(
new Dynamic_Proxy_Function(
boost::bind(&eval_function<Eval_System>, boost::ref(ss), node->children.back(), param_names, _1), numparams)));
}
/**
* Evaluates a scoped block. Handles resetting the scope after the block has completed.
*/
template <typename Eval_System>
Boxed_Value eval_block(Eval_System &ss, TokenPtr node) {
Boxed_Value retval;
unsigned int i;
ss.new_scope();
for (i = 0; i < node->children.size(); ++i) {
try {
retval = eval_token(ss, node->children[i]);
}
catch (const chaiscript::Return_Value &rv) {
ss.pop_scope();
retval = rv.retval;
throw;
}
catch (...) {
ss.pop_scope();
throw;
}
}
ss.pop_scope();
return retval;
}
/**
* Evaluates a return statement
*/
template <typename Eval_System>
Boxed_Value eval_return(Eval_System &ss, TokenPtr node) {
Boxed_Value retval;
if (node->children.size() > 0) {
retval = eval_token(ss, node->children[0]);
}
else {
retval = Boxed_Value();
}
throw Return_Value(retval, node);
}
/**
* Evaluates a break statement
*/
template <typename Eval_System>
Boxed_Value eval_break(Eval_System &, TokenPtr node) {
throw Break_Loop(node);
}
/**
* Top-level evaluation dispatch for all AST node types
*/
template <typename Eval_System>
Boxed_Value eval_token(Eval_System &ss, TokenPtr node) {
switch (node->identifier) {
case (Token_Type::File) :
return eval_file(ss, node);
break;
case (Token_Type::Id) :
return eval_id(ss, node);
break;
case (Token_Type::Float) :
return eval_float(ss, node);
break;
case (Token_Type::Int) :
return eval_int(ss, node);
break;
case (Token_Type::Quoted_String) :
return eval_quoted_string(ss, node);
break;
case (Token_Type::Single_Quoted_String) :
return eval_single_quoted_string(ss, node);
break;
case (Token_Type::Equation) :
return eval_equation(ss, node);
break;
case (Token_Type::Var_Decl) :
return eval_var_decl(ss, node);
break;
case (Token_Type::Expression) :
return eval_expression(ss, node);
break;
case (Token_Type::Comparison) :
case (Token_Type::Additive) :
case (Token_Type::Multiplicative) :
return eval_comp_add_mul(ss, node);
break;
case (Token_Type::Array_Call) :
return eval_array_call(ss, node);
break;
case (Token_Type::Negate) :
return eval_negate(ss, node);
break;
case (Token_Type::Not) :
return eval_not(ss, node);
break;
case (Token_Type::Prefix) :
return eval_prefix(ss, node);
break;
case (Token_Type::Inline_Array) :
return eval_inline_array(ss, node);
break;
case (Token_Type::Inline_Range) :
return eval_inline_range(ss, node);
break;
case (Token_Type::Inline_Map) :
return eval_inline_map(ss, node);
break;
case (Token_Type::Fun_Call) :
return eval_fun_call(ss, node);
break;
case (Token_Type::Dot_Access) :
return eval_dot_access(ss, node);
break;
case(Token_Type::If) :
return eval_if(ss, node);
break;
case(Token_Type::While) :
return eval_while(ss, node);
break;
case(Token_Type::For) :
return eval_for(ss, node);
break;
case (Token_Type::Def) :
return eval_def(ss, node);
break;
case (Token_Type::Lambda) :
return eval_lambda(ss, node);
break;
case (Token_Type::Block) :
return eval_block(ss, node);
break;
case (Token_Type::Return) :
return eval_return(ss, node);
break;
case (Token_Type::Break) :
return eval_break(ss, node);
break;
default :
return Boxed_Value();
}
}
}
#endif /* CHAISCRIPT_EVAL_HPP_ */